fix(web): renumber following items when inserting into a numbered list

[saphid]

Model: Claude Opus 5.5 and Claude Sonnet 5.5. Rebased onto current main with Claude Opus 5.5 on 2026-10-12.

What Changed

In the composer, Shift+Enter inside a numbered list now renumbers the items below the new one, not just the new item itself.

listContinuationForEnter (apps/web/src/composer-list-continuation.ts) now also rewrites the numbers of the ordered items that follow:

• It walks the contiguous run of items at the same indent width and delimiter.
• It skips deeper-indented children and lines that sit inside a multi-line chip.
• It stops at a blank line or a shallower line.
• Items that are already in sequence are left untouched. Explicitly zero-padded markers (01.) keep their width; others don't gain padding.

The edit now carries an explicit expanded cursorAfter so the caret still lands right after the new marker even though the replaced range extends past it. Tab uses the same field with its previous offset.

Why

Put the caret at the start of an earlier item's text and press Shift+Enter to push it down. The pushed item gets the next number, but everything below keeps its old number, leaving duplicates (1. 2. 3. 3.). Enter only ever inserted a single marker and never looked at later lines. Fixing it where the marker is inserted keeps both composer modes identical, because they share this store-replacement path.

Bullets, tasks, the empty-item exit path, and non-list lines behave as before.

UI Changes

Fresh attached-preview verification on disposable data. Same project, list and viewport on current main c18e5ea and clean candidate d630285. At the end of item 2, press Shift+Enter and type into the inserted item.

Before (current main): the following item keeps 3, leaving duplicate numbers.

After (candidate): the following item becomes 4; typing stays in the inserted item.

Full recordings: before · after. GIFs show the first seven seconds sampled at 10 fps, at real-time speed, cropped to the full composer and heading. Recordings retain the full viewport. Screenshots: before · after.

Verification

• Five focused composer suites: 220 tests passed, exit 0. Keeping the new regression tests on baseline source produces 8 failures; restoring the candidate passes all 19 list tests.
• Web typecheck passed. Scoped lint has no errors and no new warnings; its 43 warnings match the baseline.
• Live preview: middle-list insertion and caret placement pass in rich and literal modes. Cmd+Z restores the original list. File-chip insertion, splitting after the chip, and Tab indentation preserve the chip and text.
• Fresh independent GPT-6 Astra review through Codex found no correctness blockers. A nonblocking performance observation remains for unusually large lists: token scanning grows with lines × chips.
• Desktop shares the web composer but was not run separately. Mobile uses its own composer and is unaffected. No provider message was submitted during verification.

Original implementation: Claude Sonnet 5.5 and Claude Opus 5.5 in Claude Code. Readiness audit: GPT-6.1 Sol through Codex. Independent review and attached-preview verification: GPT-6 Astra through Codex in T3 Code.

[macroscopeapp]

Approvability

Verdict: Approved at d630285

Macroscope's review found this PR approvable — The PR is a localized web composer bug fix that renumbers only the affected ordered-list run and preserves existing behavior for other composer paths. Its production changes are self-contained and accompanied by focused regression coverage, with no schema, deployment, security, billing, or static-analysis changes.

Notes:

• Diff unchanged. Approvability was decided on eligibility alone.

No code changes detected at 7a14a35. Prior analysis still applies.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository: pingdotgg/t3code/.coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: 6d2c4faf-588f-4d74-b82e-a9e3d99e977a

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📥 Commits

Reviewing files that changed from the base of the PR and between 8792f95 and d630285.

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📒 Files selected for processing (3)

• apps/web/src/components/chat/ChatComposer.tsx
• apps/web/src/composer-list-continuation.test.ts
• apps/web/src/composer-list-continuation.ts

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📝 Walkthrough

📝 Walkthrough

Walkthrough

Enter continuation can renumber matching ordered-list items below the current item. List edits now return explicit caret offsets, which ChatComposer applies after Enter and Tab edits.

Changes

Composer list editing

Layer / File(s)	Summary
List continuation and edit results apps/web/src/composer-list-continuation.ts, apps/web/src/composer-list-continuation.test.ts	List edits return the caret offset after the edit. Enter continuation can renumber following ordered items with matching indentation and delimiter. The scan accounts for inline chips and stops at blank or nonmatching lines. Tests cover numbering, boundaries, caret placement, and chip offsets.
Apply returned caret offsets apps/web/src/components/chat/ChatComposer.tsx	Enter continuation and Tab indentation use edit.cursorAfter to set the caret.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

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Merge Risk: ⚪ Minimal · up to d6302

The list-renumbering and caret updates have no identified merge-blocking issue. Mergeable after normal checks; runtime editor interaction was not independently exercised.

Security Architecture Review

Security architecture risk: ⚪ Minimal · up to d6302

The change remains within local composer editing. It preserves structured references, existing input restrictions, and submission behavior while correcting numbering and caret placement. No material security risk was identified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The effective changed surface is the current composer prompt and its caret. The inspected path grants no additional service, tenant, tool, credential, or context-payload authority.

Trust Boundaries and Controls

• observed — User-authored prompt text remains input to a local text transformation. Carets inside inline tokens are rejected, multiline-chip interiors are skipped, and intervening chip source is preserved rather than interpreted or rewritten.

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Pre-merge checks | 4 | 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 60.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 10 functions across 3 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Title check		The title clearly and concisely describes the main change: renumbering following items in a numbered list when inserting an item.
Description check		The description is detailed and covers the problem, implementation, behavior changes, UI evidence, verification results, limitations, and agent attribution. It does not use the template headings exact…

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• Fix all pre-merge checks with AI

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

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Dismissing prior approval to re-evaluate d630285

[saphid]

Review requested

Date (UTC)	Reviewer	Where
2026-10-03	Julius	Discord DM

_{Logged so this PR shows when a maintainer was asked to review it.}

[saphid]

Review requested

Date (UTC)	Reviewer	Where
2026-10-06	Maria	Discord DM

_{Logged so this PR shows when a maintainer was asked to review it.}